CN103820307B - Novel mechanical stirring impeller micro-membrane aeration bioreactor - Google Patents

Abstract

The present invention is a new type mechanical stirring impeller aeration bioreactor. The bioreactor adopts micro-film aeration stirring impeller. connected, and the overall balance is achieved by the central positioner (10); the impeller is composed of a micro-membrane stirring aeration blade and a stirring shaft sleeve with anti-wire locking, and the overall diameter of the impeller of the agitator is 0.15~ 0.5 times; the blade angle of the impeller is 17 ⁰ 40 ^/? ; The installation angle between the blade and the stirring shaft sleeve is 45 ⁰ or 60 ^0? . The rotation of the agitating impeller makes the membrane and the solution form a cross-flow, which continuously scours the surface of the membrane to prevent the clogging of the aeration membrane holes. It is preferred that the propelling blades can meet the high oxygen consumption and low shear fermenter. Preferably, the sealed connection of the bioreactor as shown in Figure 2 and Figure 3 adopts a special locking and anti-wire method, which not only prevents fermentation pollution but also facilitates dismantling and repairing.

Description

A new mechanically stirred impeller micro-film aerated bioreactor

technical field

The invention belongs to the field of mechanically stirred bioreactors, and relates to a mechanically stirred bioreactor for impeller micro-film aeration.

Background technique

As a new type of high-efficiency fermentation reactor, micro-membrane bioreactor is becoming more and more active in the current fermentation industry, and has been gradually applied to gas aeration in liquid fermentation tanks. The membrane bioreactor technology of Yang Tao et al. (CN101503245A) has not only been widely used in the field of sewage treatment, but in recent years, relevant scholars at home and abroad have made many attempts on whether micro-membrane aeration can be used to enhance oxygen transfer in microbial cultivation. It was found that micro-membrane aeration (Chen Fei et al. CN101659476A) has a significant effect on the improvement of fermentation yield and energy saving, so it has been paid attention by relevant scholars at home and abroad.

The mechanical agitation and ventilated fermenter uses the function of a mechanical agitator to fully mix the air and the fermentation liquid to promote the dissolution of oxygen in the fermentation liquid, so as to ensure the supply of oxygen required for the growth, reproduction and fermentation of microorganisms. Mechanical agitation and ventilated fermenters can be used in most biological processes, such as glutamic acid, citric acid, enzyme preparations, antibiotics, yeast and other fermentation equipment. Mechanical agitation and ventilated fermenter is the most widely used fermenter at present. It has good usability, strong applicability, and easy expansion. It can be applied in the process of microbial cultivation from small to large. However, the air distributors of almost all mechanically agitated and ventilated fermenters adopt the perforation method, resulting in large and uneven particle size of the air bubbles, which need to be crushed by agitation, resulting in high agitation power and high shear force. Oxygen low shear microbial cultures are not used. Therefore, many experts and scholars consider using micro-membrane aeration (Liao Zhimin et al. CN201381249Y) to solve this problem. However, although the membrane bioreactor is an efficient new fermentation aeration technology, there are still some defects. During the fermentation process of the membrane bioreactor, the membrane pores can not only distribute uniform and fine air bubbles, but also be blocked by macromolecular solutes. Therefore, the problem of membrane fouling is the main reason why membrane bioreactors are widely used in the field of fermentation.

Contents of the invention

The technical problem to be solved by the present invention is to provide a new type of high-efficiency mechanical stirring impeller micro-film aeration bioreactor, the micro-film aeration solves the problem of high shear force, high energy consumption and general micro-film aeration The high pollution of the membrane has a short service life, which is not conducive to the problem of high dissolved oxygen and low shear fermentation.

In order to solve the above-mentioned technical problems, the air duct of the mechanically stirred impeller micro-film aerated bioreactor of the present invention is connected to the rotating shaft through a mechanical seal, and the rotating shaft passes through the sealing coupling and then passes through the mechanical seal of the mechanically stirred reactor tank body. It is connected with another rotating shaft, which is connected with the micro-membrane aeration stirring impeller. Through the addition of the sealing coupling, the rotating shaft and the micro-membrane aeration stirring impeller, the traditional bioreactor is improved as a whole, and the mechanical stirring is overcome. The air bubble particle size of the ventilated fermenter is large and uneven, and it is easy to dismantle and repair as a whole.

Preferably, when there are two micro-membrane aeration stirring impellers, the impellers are connected by a rotating shaft, and the overall balance is achieved by a central positioner.

Preferably, the micro-membrane aeration stirring impeller is composed of a micro-membrane stirring aeration blade and a stirring shaft sleeve (12) with anti-wire locking, and the overall diameter of the impeller of the agitator is 0.15 to 0.5 times the diameter of the tank (1).

Preferably, the knuckle angle of the impeller is 17 ⁰ 40 ^/ , and the installation angle between the impeller and the stirring shaft sleeve is 45 ⁰ or 60 ⁰ .

Through the special structural design of the impeller, the use of micro-membrane blades can solve the problem of difficult cleaning and bacterial contamination due to the negative pressure formed behind the hollow blades when the impeller rotates to suck the culture medium and bacteria into the hollow blades and deposit them. At the same time, due to the rotation of the impeller, the membrane and the solution form a cross flow, which continuously scours the surface of the membrane to prevent the clogging of the aeration membrane holes. Moreover, the integral connection and structural design of the present invention are well disassembled and sealed, which reduces energy consumption and improves efficiency.

Preferably, the number of blades is 4 or 6, which further improves the efficiency of the blades.

Preferably, the blades are propulsive, which further improves the overall mixing of the fermentation broth, reduces the shear force of the agitator, and reduces the stirring power, so as to achieve the effect of energy saving.

Preferably, when there are more than two impellers, the impellers are arranged equidistantly from 800 to 1000 mm, and the installation height of the bottom impeller is 1 to 1.5 times the diameter of the impeller, so that the gas distributor is installed at the bottom of the reactor, which is easy to It is difficult to clean and dredge after the blockage occurs, and there is also the problem of sanitary dead angle. The aeration effect of the impeller is further optimized. The number of impellers is determined according to the size of the fermenter.

Preferably, the sealed coupling is a special sealed coupling, which means that the two shafts must be concentrically and firmly connected, and the fermentation sealing effect must also be achieved. Specifically, this technical problem is solved in the following way: the sealed shaft coupling is fixed on the lower end of the rotating shaft in a locking anti-wire manner, the rotating shaft has an O-ring, and is sealed with the inner ring of the sealed shaft coupling in a sinking way. , and then locked with the outer wire of the rotating shaft through the inner wire of the sealing coupling; the two ends of the rotating shaft connected to the impeller also have locking anti-wires and O-rings respectively, and the aforementioned sealing coupling and The connection between the rotating shafts is sealed with the impeller. The special structural design of these accessories is convenient for disassembly and maintenance and realizes the requirement of preventing fermentation and contamination.

Preferably, the upper part of the rotating shaft connected to the sealed coupling is provided with a keyway, and the auxiliary pulley drives the rotating shaft, further improving the efficiency.

Positive effects of adopting the above technical solutions: (1) The use of mechanical seals and detachability solves the problem that if the gas distributor is blocked and difficult to clean and dredge, it makes the bioreactor less susceptible to bacterial contamination during the microbial cultivation process. (2) The use of micro-membrane blades can solve the problem of difficult cleaning and bacterial contamination due to the negative pressure formed behind the hollow blades when the impeller rotates to suck the culture medium and bacteria into the hollow blades for deposition. At the same time, due to the rotation of the impeller, the membrane and the solution form a cross flow, which continuously scours the surface of the membrane to prevent the clogging of the aeration membrane holes. (3) Due to the use of micro-membrane blades for air distribution, the particle size of the distributed bubbles is small, so there is no need to rely on the stirring action of the impeller to disperse them. Therefore, the agitator can be made into a variety of axial flow agitators with low shear force, which not only solves the overall mixing problem of the bioreactor, but also solves the problem of high shear force.

Description of drawings

Fig. 1 is a structural assembly diagram of the present invention;

Fig. 2 is a sectional view of No. 4 transmission shaft in Fig. 1;

Fig. 3 is a sectional view of No. 5 coupling in Fig. 1;

Fig. 4 is the cross-sectional view of No. 7 and No. 9 rotating shafts in Fig. 1;

Fig. 5 is the sectional view of No. 8 microfilm aeration stirring impeller among Fig. 1;

Fig. 6 is the sectional view of No. 11 microfilm aeration stirring impeller among Fig. 1;

Fig. 7 shows the kink angle θ2 of the micro-membrane aeration stirring impeller, and the installation angle θ1 between the impeller and the stirring shaft sleeve.

In the figure, 1 is a mechanically stirred reactor, 2 is an air duct for sterile air intake, 3 is a mechanical seal, 4 is a transmission shaft, 5 is a seal coupling, 6 is a mechanical seal for a fermentation tank, 7 is a rotating shaft, and 8 is a microfilm exposure Pneumatic stirring impeller, 9 rotating shafts, 10 fixed center positioner, 11 microfilm aeration stirring impeller, 12 stirring shaft sleeve.

detailed description

The technical scheme of the present invention will be further described below in conjunction with the accompanying drawings, but it should not be construed as a limitation of the present invention. In the present invention: the dynamic and static connection is that the air duct and the rotating shaft are connected through a mechanical seal, and the air duct is the end face of the moving ring and the rotating shaft. The end face of the static ring of the shaft is connected, and the structure of the mechanical seal is a mechanical seal for a special fermenter with a single end face, multiple springs, and rotating screws. It is characterized in that the static ring seal between the static ring and the rotating shaft flange adopts flat Gasket sealing ring is used for sealing, and the static ring is split.

Fig. 1 is a structural assembly diagram of the present invention, Fig. 2 is a sectional view of No. 4 transmission shaft in Fig. 1, Fig. 3 is a sectional view of No. 5 coupling in Fig. 1, Fig. 4 is a sectional view of No. 7 and No. 9 rotating shafts in Fig. 1 Axial sectional view, Fig. 5 is the sectional view of No. 8 microfilm aeration stirring impeller in Fig. 1, Fig. 6 is the sectional view of No. 11 microfilm aeration stirring impeller in Fig. 1, Fig. 7 is the microfilm aeration stirring impeller in Fig. 1 The kink angle θ2 of the impeller, and the installation angle θ1 between the impeller and the stirring sleeve.

As shown in Figure 1, the air duct 2 of the impeller micro-film aerated bioreactor is connected to the rotating shaft 4 through the mechanical seal 3, and the rotating shaft 4 passes through the sealing coupling 5 and then through the mechanical seal 6 on the tank 1 and the rotating shaft 7 Connection, the rotating shaft 7 is connected with the micro-membrane aeration stirring impeller 8 of special structure, the micro-membrane aeration stirring impeller 8 and the micro-membrane aeration stirring impeller 11 are connected through the rotating shaft 9, and the overall balance is achieved by the center positioner 10. As shown in Figure 5 and Figure 6, the micro-membrane aeration stirring impellers 8 and 11 are composed of micro-membrane stirring aeration blades and a stirring shaft sleeve (12) with anti-wire locking, the two ends of the micro-membrane aeration stirring impeller 8 are open, The lower port of the micro-film aeration stirring impeller 11 at the bottom is closed. Obviously, the specific number of the impellers is not limited to two of the present embodiment, but is determined according to the size of the fermenter, which can be 1 or more than 3. Arranged equidistantly from the impeller at 800-1000 mm; the overall diameter of the impeller of the agitator is 0.15-0.5 times the diameter of the tank (1), which is adjusted according to different fermentation systems. The installation height of the bottom impeller is 1-0. 1.5 times, the knuckle angle of the impeller is 17 ⁰ 40 ^/ ; the installation angle of the impeller and the stirring sleeve is 45 ⁰ or 60 ⁰ ; the number of blades is 4 or 6.

As shown in Figure 2, Figure 3 and Figure 4, the sealed coupling 5 is fixed on the lower end of the rotating shaft 4 in a locking and anti-wire manner, and the rotating shaft 4 has an O-ring, and is inserted in a sinking manner. It is sealed with the inner ring of the sealing coupling 5, and then the inner thread of the sealing coupling 5 is locked with the outer thread of the rotating shaft 4, and the rotating shaft 4 is provided with a keyway. The special structural design of these accessories is required for the convenience of disassembly and maintenance and the prevention of fermentation contamination.

The principle of the present invention is: when the fermentation tank is sterilized, the steam enters the stirring hollow shaft through the air duct to reach the blades of the micro-membrane aeration stirring impeller, and through the membrane holes, it is evenly distributed in the solution by means of the centrifugal action of the stirring impeller to reach the For disinfection purposes of road and fermentation broth. Therefore, the present invention adopts high temperature resistant lubricating oil to the two bearings of the transmission part, and also adopts a water cooling system to prolong the service life of the bearings. During the cultivation process, the sterile air reaches the blades of the stirring impeller with a micro-membrane structure through the hollow shaft, and the air bubbles are evenly distributed in the solution by the centrifugal action of the stirring impeller, and then the fluid turbulence is promoted by the impelling action of the stirring impeller, increasing The mass transfer coefficient of the reactor. At the same time, use the rotation of the stirring impeller to form a cross-flow between the membrane and the solution, and continuously wash the surface of the membrane to prevent the clogging of the aeration membrane holes. At the same time, the special structural design of the main body of the micro-membrane stirring blade does not require a stirring impeller to crush the air bubbles, so the stirring blade can be made into various structures to meet different fermentation systems. However, if a low-shear and high-mixing paddle is used, the stirring power can be reduced and the overall fermentation cost can be reduced.

Example: Arachidonic acid (ARA) fermentation system of a company

Arachidonic acid (ARA) is fermented and produced by Mortierella alpina, a filamentous fungus that is afraid of high shear force in bioreactors. If the fungus is chopped, the fungus grows The required oxygen transfer not only affects the yield but also makes the subsequent separation difficult. Therefore, more air-lift fermenters are generally used now, but the air-lift fermenters have the disadvantages of high energy consumption such as large gas flux and poor cooling effect. Arachidonic acid (ARA) fermentation is a typical high-oxygen low-shear fermentation system. Arachidonic acid (ARA) fermentation culture temperature is 28°C, pH is 6.0, DO is not less than 20%. The formula is: 10% glucose, 0.5% yeast extract, 0.3% beef extract, 0.15% MgSO ₄ , 0.3% KH ₂ PO ₃ . A company used a conventional 5M ³ fermenter to cultivate the result that the dry mass of the bacteria was 32g/L, the oil was 40g/L, and the ARA was 38g/L. However, the same 5M ³ new mechanical stirring impeller micro-film aerated fermenter results in the dry mass of bacteria being 40g/L, the oil content being 50g/L, and the ARA being 45g/L. The fermentation level has been greatly improved and reached the international leading level.

In the invention, the aseptic air passes through the hollow shaft to the stirring blade of the micro-membrane structure in the strict purebred cultivation process, and the air bubbles are evenly distributed in the solution by the centrifugal action of the stirring impeller to achieve mass transfer. At the same time, the stirring blades can be made into various forms of blades, especially the push-type low-shear force agitator to meet the high oxygen consumption and low-shear fermentation system. In addition, through this special sealing connection method, disassembly and maintenance can be greatly facilitated.

Claims (7)

1. the micro-membrane aerated bioreactor of churned mechanically impeller, comprise mechanical stir-reactor (1), it is characterized in that: the airduct (2) of the micro-membrane aerated bioreactor of described impeller is connected with the first rotation axis (4) by mechanical seal (3), first rotation axis (4) is connected with the second rotation axis (7) by the fermentor tank tank body mechanical seal (6) on mechanical stir-reactor (1) tank body by special sealing shaft joint (5) again, and the second rotation axis (7) is connected with the second mocromembrane aeration agitation impeller (11);

Described special seal shaft joint (5) is fixed on the lower end of the first rotation axis (4) in locking reverse silk mode, described the first rotation axis (4) is with O type circle, and insert mode and the inner ring seal of sealing shaft joint (5) with heavy, then locked by sealing shaft joint (5) internal thread and the first rotation axis (4) outer silk; Described the second rotation axis (7) and the 3rd rotation axis (9) two ends respectively with the anti-silk of tight lock and O type circle, and are connected with impeller seals with the mode of connection between the first rotation axis (4) with above-mentioned sealing shaft joint (5);

Described the second rotation axis (7) is connected with the first mocromembrane aeration agitation impeller (8), first mocromembrane aeration agitation impeller (8) is connected by the 3rd rotation axis (9) with the second mocromembrane aeration agitation impeller (11), and reaches whole machine balancing by central positioner (10);

The first described mocromembrane aeration agitation impeller (8) and the second mocromembrane aeration agitation impeller (11) stir aeration blade by mocromembrane and have the stirring axle sleeve (12) that anti-silk tightly locks and form, first mocromembrane aeration agitation impeller (8) both ends open, close in the second mocromembrane aeration agitation impeller (11) lower port of the lowest layer, the second mocromembrane aeration agitation impeller (11) mounting height is 1 ~ 1.5 times of impeller diameter.

2. the micro-membrane aerated bioreactor of impeller according to claim 1, is characterized in that: the integral diameter of the first described mocromembrane aeration agitation impeller and the second mocromembrane aeration agitation impeller is 0.15 ~ 0.5 times of reactor (1) diameter.

3. the micro-membrane aerated bioreactor of impeller according to claim 1, is characterized in that: the knuckle θ 2 of the first described mocromembrane aeration agitation impeller and the second mocromembrane aeration agitation impeller is 17 ⁰40 ^/, described impeller is 45 with the setting angle θ of stirring axle sleeve ⁰or 60 ⁰.

4. the micro-membrane aerated bioreactor of impeller according to claim 3, is characterized in that: the number of described blade is 4 or 6.

5. the micro-membrane aerated bioreactor of impeller according to claim 3, is characterized in that: described blade is for pusher.

6. the micro-membrane aerated bioreactor of impeller according to claim 2, it is characterized in that: when the impeller of the first described mocromembrane aeration agitation impeller and/or the second mocromembrane aeration agitation impeller is two or more, impeller and impeller are 800 ~ 1000 millimeters of equidistant arrangements, and lowest layer impeller mounting height is 1 ~ 1.5 times of impeller diameter.

7. the micro-membrane aerated bioreactor of impeller according to claim 1, is characterized in that: the top of described the first rotation axis (4) is provided with a keyway.